Surgery Flashcards
What defines oligouria?
< .5 mL/kg/hour
How often does uterine perforation occur during hysterosocpy procedure?
What increases this risk?
1.5%
Cervical stenosis, uterine scar tissue
What is the most valuable in detecting gas embolus intraoperatively?
End Tidal CO2
Other signs:
- Tachycardia
- Arrhythmia
- Hypotesnion
- Increased CVP
- Mill Wheel Murmur
- Cyanosis
**Capnography or capnometry are more valuable than oximetry in detection of gas embolus because the end tidal CO2 decreases because of a decrease in cardiac output and increase in dead space
What should you do if you suspect a gas embolis intraoperatively?
Release of pneuoperitoneum
Place in steep trendelenberg
Position on the left side
100% fiO2
Hyperventilate to help elimination of CO2
Which generation of cephalosporin is the first line of choice for preoperative gynecologic surgical procedures?
Ancef (Cefazolin) is a first generation cephalosporin
Branches of anterior division of internal iliac artery?
Uterine Umbilical Superior vesical Obturator Internal pudendal Inferior Gluteal Middle Rectal Vaginal
Branches of posterior division of internal iliac artery?
Superior gluteal
Lateral Sacral
Iliolumbar
In order to expand the uterine cavity with distension media during hysteroscopy, what pressure in mmHg must be reached?
To expand the cavity intrauterine pressures of these media must reach 45-80 mmHg
Hysteroscopic distension medium that is electrolyte rich and can use BIPOLAR cautery?
LR/NS
What is the maximum fluid deficit allowed for LR/NS?
2,500 mL
During hysteroscopy, what mediums allow you to use monopolar cautery?
Glycine
Sorbitol
Mannitol
*Electrolyte POOR
What is the maximum fluid deficit allowed for Glycine/Sorbitol/Mannitol?
1,000 mL
Risk of using low viscosity, electrolyte poor solutions for hysteroscopy? (Glycine, Sorbitol, Mannitol)
Can cause hyponatremia
Decreased serum osmalality
Potential for cerebral edema and death
Venous drainage of ovaries?
Right ovarian vein drains into inferior vena cava
Left ovarian vein drains into left renal vein
Describe the route of the ureter
Total length ~ 30 cm (15 in abdomen, 15 in pelvis)
Commences at renal pelvis
Descends over psoas muscle (lateral to medial)
Enters pelvic brim at the bifurcation of the common iliac vessels
Descends along side wall posterior to ovarian fossa
Crosses under the cardinal ligament/under uterine artery
Goes anteromedial and inserts in the bladder
Risk factors for intraoperative cystotomy?
- Previous pelvic surgery (C/S)
- Inflammatory Disease/adhesions (endometriosis)
- Mass Distortion of local anatomy (fibroids in lower uterine segment)
- Operator experience
Pros/Cons of cystoscopy at time of hysterectomy?
Pros:
- Quick safe/proceudre
- Improve skills + interpretation of results
- Could identify injury intra operatively
Cons:
- Increased risk of infection
- Increased time of procedure
*has not been shown to improve detection of intraoperative ureteral injury
How long does it take for the bladder to re-epitheliaze?
3-4 days
When is a voiding cystourethrogram indicated (rather than a voiding trial)?
- Large defect > 2 cm
- If foley is removed less than 7 days
Considerations when repairing a cystotomy?
- Location relative to trigone
- Ureteral assessment
- Closure in 2 or 3 layers
- Check for leaks/cysto
- Foley catheter 3-7 days
- Voiding trial or voiding cystourethrogram
Are antibiotics needed for intra operative cystotomy or while catheter is in place?
Nope!
Layers of closure for the bladder
Mucosa/submucosa = 3-0 vicryl running
Muscularis = 3-0 vicryl interrupted
Bladder Serosa = 2-0 vicryl interrupted
Describe steps of cystotomy repair
Assess location relative to trigone
Need for ureteral stents? Consult Urology
Bladder dome injury:
- Close mucosa/submucosa with 3-0 vicryl running
- Close musclaris with 3-0 vicryl interrupted
- Close bladder serosa with 2-0 vicryl interrupted
- Cystoscopy/Bladder instillation to check for leaks
- Replace foley catheter, leave in p lace 3-7 days
- Voiding trial on Day #7
- If large injury- do voiding cystourethrogram (or if foley removed prior to day 7)
NO ANTIBIOTICS NEEDED
Most common sites ureteral injury?
- Clamping IP ligament
- Clamping uterine artery
- Near uterosacral ligament
- Closing vaginal cuff
Repair of ureteral injury > 5 cm above UVJ
Direct end-end reanastomosis
(uretero-ureterostomy)
- Spatulate the ureteral ends
- 4-6 interrupted sutures of 4-0 vicryl
- Ureteral stents + foley catheter x 10 days
Repair of ureteral injury < 5 cm above the UVJ
Bladder re-implantation
(Uretero-neocystotomy)
What to do if there is too much tension to do an end-end re anastomosis or bladder re-implantation?
Psoas Hitch - pulling the bladder to the ureter by attaching it to the psoas muscle
Boari Flap - essentially the same thing, using the bladder to form a longer tube to connect to the ureter
Basics of bowel injury
Always close the injury perpendicular to the long axis of the bowel
If laceration is parallel to long axis = do end to end closure
If laceration is perpendicular to long axis to side to side closure
Additional antibiotics needed for a bowel injury?
Small bowel - no additional if pt received her pre op abs
Large bowel - YES, add dose of Flagyl
*No post op dietary restrictions necessary
*Do NOT need routine NG tube placement
Nerves likely to be injury during a transverse abdominal incision?
Iliohypogastric and ilioinguinal
If transected: Small triangular area of numbness above incision, apex toward umbilicus. Resolves in 6 months
If entrapped by lateral sutures: sharp, burning pain. Radiates from incision to suprapubic area, labia or thigh. Relief with infiltration of local anesthetic
Concern for which nerve with very deep or lateral placement of side wall retractors?
Or excessive hip adduction with vaginal surgery?
Femoral
Sensory deficit of anterior/medial thigh
Motor weakness of hip flexion and knee extension
90% resolve spontaneously
What could cause a foot drop? And sensory loss over dorsum of foot and lateral shin?
Use of Allen supporting leg/foot rests in vaginal surgery caused by the upper lateral tibial area
Injury to PERONEAL nerve
Resolves spontaneously in 3-6 months
How to avoid nerve injuries during surgery?
- Avoid hyperextension and flexion when positioning
- Use padding to minimize compression
- Avoid lateral extension of transverse incisions beyond the border of the rectus muscle
- Retractors should not compress the psoas muscles
- Identify the obturator nerve when performing extensive dissection in the obturator fossa
Define post op fever
Fever >/= 100.4 on two occasions at least 4 hours apart excluding the first 24 hours post op
OR
one temp greater than 101.5 F
Fever 1-2 days post op
Bowel obstruction/ileus
Pneumonia
Fever 2-5 days post op
“water”
uTI
Fever 3-5 days post op
“Wound”
Surgical site infection
Fever 7-10 days post op
“Walk”
DVT
“Hectic” fever, elevated baseline temp with spikes after surgery
Seen with Eosinophilia
Patient looks better than temp suggests
Review medication list!
“Wonder Drug”
Consider septic pelvic thrombophlebitis (Tx is Gent/Clind + LMWH) if fever persistent fever after 3-5 days of antibiotics and no evidence of abscess
Cons of using the Robot?
More surgical incisions
Lack of high quality evidence to show superiority
Attempting procedure beyond skill
Increased cost
Lack of haptic feedback
Why do you use robotics?
- Extensive robotic training in residency
- Experienced assistant is not available (work with NP with 2 years of OR experience, similar to intern level skills)
- Better visualization, able to operate at lower insufflation levels to help with pain
- Better fine motor control with articulated instruments
- Able to use minimally invasive approach for more complex cases (fibroids/endometriosis)
- Better detection of endometriosis lesions
Compared to TAH:
- Similar OR time
- Less blood loss
- Lower complication rate
- Shorter hospital stay
What would you do in a pt that declines a pre-op EMB biopsy, but the D&C you did prior to ablation comes back with hyperplasia or EIN?
Refer to GYN Oncology for hysterectomy. There is a 3-50% chance of concurrent carcinoma at the time of hysterectomy
Pt will need sLND, peritoneal washings + frozen section
Counseling on endometrial ablation
- Harder to assess the lining later on, need to do pre-op EmBx
- Need to do TVUS to asses uterine cavity
- Need RELIABLE contraception and risks of pregnancy following an ablation
- Review DECREASED flow, and not absent menstrual flow
Things associated with higher failure rate of endometrial ablation?
- Large cavity size > 10 cm
- Adenomyosis
- Grand multi-parity
- Younger age
- Acute ante/retro flexion
- Intra cavitary lesions (fibroid or polyp)
Contraindications to an ablation?
- CANCER or hyperplasia
- Current pregnancy
- Desires future pregnancy
- Acute pelvic infection
- IUD in place
“relative” contraindications
- increased risk of hyperplasia (obesity/LYNCH/tamoxifen)
- postmenopausal women
Risk of removal of ovaries before age 50?
- Increased CV risk
- Negative impact bone health
- Negative impact on cognitive function
- Negative impact on overall mortality
Risk of pre-menopausal oophorectomy?
- Increase is CVD
- Increase in Stroke
- Cognitive impairment
- Dementia
- Parkinson’s disease
- Glucoma
- CKD
- Osteoporosis
- Increase all cause mortality
- Increase sexual dysfunction
Risks of laparoscopic surgery?
Infection
Bleeding
Injury to surrounding structures
Anesthesia risks
Medical co-morbidities
Specifically for laparoscopy: conversion to open, port site hernia
What are the layers of the anterior abdominal wall?
7 layers:
Skin
Subcutaneous tissue
Fascia
Anterior rectus sheath
Rectus muscles
Posterior rectus sheath (if above arcuate line)
Pre-peritoneal fat
Peritoneum
Options for abdominal entry?
Umbilicus
- Veress
- Direct visualization
- Hassan technique
Palmer’s point : 2 cm below the costal margin at the mid clavicular line
How do you confirm safe entry into the abdomen?
What general steps can be taken to increase the safety during abdominal entry?
- Pull back on the syringe to make sure there is no blood or stool
- Saline drop test
- Opening pressure < 5 mm Hg
- Supine positioning
- Awareness of anatomy and proximity of major vasculature, and angle of veress needle
- Draining the bladder
- Decompress the stomach
- Switching techniques if not able to enter
If you have numbness around Pfannensteil incision, which nerve is likely transected?
Iliohypogastric
Name the layers of the abdomen above the arcuate line
Skin
Subcutaneous tissue
Anterior rectus sheath (external + internal oblique)
Rectus muscles
Posterior rectus sheath (Transversalis + interntal oblique)
Preperitoneal fat
Peritoneum
Off what vessel does the inferior epigastric artery arise?
Branch of the external iliac
Runs medial to the lateral border of the rectus
Creates the “lateral umbilical fold”
Goals of ERAS protocol?
Shorter length of stay
decreased Post op pain
More rapid return of bowel function
decreased complication/readmission rates
Increased patient satisfaction
Components of ERAS
Avoid prolonged fasting
Regional anesthesia
Maintenance of normothermia
Early mobilization
Virchow’s Triad
Hypercoagulable state
Stasis
Irregular vessel wall (endothelial damage)
What types of things are considered in the caprini score?
Age
Route of surgery (open vs. lsc)
BMI
Hx of DVT/thrombophilia
OCPs/HRT use
How does the Caprini score stratify risk?
Low = 1.5% VTE risk
Moderate risk = 3% risk
High risk = 6% risk
Management of Caprini score > 5?
SCDs
Extended anticoagulation after surgery
LMWH 28 days
If high risk of bleeding, wait to start until bleeding risk is lower
What patient would be a candidate for SCDs and perioperative anticcoagulation?
Caprini score 3-4
Always use SCDs then could consider LDUH or LMWH if average risk of bleeding
(If high, then just use SCDs)
What is the Wells score?
Clinical assessment for pulmonary emoblism
Heparin MOA and dosing
Cofactor for antithrombin
Increases inhibition of thrombin and Factor Xa
150 u/kg loading dose > 20 u/kg/hr maintenance
Change to warfarin or SubQ 8-10k units BID
Goal PTT with Heparin?
PTT 1.5 -2.5 x normal
Reversal for Heparin?
Protamine Sulfate
Theraputic dosing for lovenox?
1 mg/kg BID
How does induction of anesthesia affect blood pressure?
Anesthesia triggers sympathetic activation that may raise systemic blood pressure by 20-30 in normotensive patients, up to 90 mm Hg in untreated patients
Should patient’s take their BP medication the morning of surgery?
In most cases answer is yes!
Abrupt cessation of beta blocks can lead to rebound hypertension
ACE + ARBS should be held. Can blunt renin activation and cause intraoperative hypotension (resume post op)
*Check electrolytes if on diuretic
What pre and intra-operative steps can be taken to decrease risk of fluid overload when doing a myomectomy
Pre-operative treatment with GnRH agonists
intraoperative injection of dilute vasopressin (0.05 U/mL).
How does the stress of surgery cause ketoacidosis and hyperglycemia in a diabetic patient?
Surgery induces a stress response with catecholamine and cortisol release, which reduces sensitivity to insulin. Adrenaline release causes glucagon release which stimulates glucose release (glycogenolysis) and gluconeogenesis. Glucagon also inhibits glucose breakdown and glycogen formation. Without glucose available the cells start using fat as main source of fuel. This induced catabolic state can lead to keto- and gluconeogenesis as well as the breakdown of proteins, and fats, leading to hyperglycemia and ketosis.
Diabetic meds on day of surgery?
Due to the risk of metabolic acidosis, metformin and other oral hypoglycemic agents should be withheld the day of surgery
Insulin management on day of surgery?
On the morning of surgery, the patient should receive 50% of their usual NPH dose or 75-80% of their usual long-acting insulin analog (e.g. glargine or detemir) or pump basal insulin dose
During surgery, the patient should be placed on a variable rate intravenous infusion of insulin for longer complex procedures - Type 1 diabetics should be maintained with a basal rate -Active management of glucose intra-operatively is important to manage the physiologic changes with the use of anesthetics, sedatives and analgesics.
Medium and short acting insulins can be used for minor procedures
Blood glucose monitoring should occur at least every 2-4 hours while patients remain NPO with additional short-acting insulin administered as needed. Can use sliding scale if missing more than one meal
